Short answers, pulled from the story.
The Council of People's Commissars issued a decree establishing the Workers' and Peasants' Red Army in January 1918. This new force aimed to oppose military adversaries during the Russian Civil War, specifically targeting groups collectively known as the White Army.
Semyon Timoshenko commanded three times more soldiers than the Finns but faced severe morale issues due to Stalin's purges during the conflict that began on the 30th of November 1939. Hostilities ceased in March 1940 with the Moscow Peace Treaty after Finnish forces inflicted stunning losses on the Red Army for the first three months.
Over 30,000 officers were executed or imprisoned before fighting started, including Marshal Mikhail Tukhachevsky who was perceived as a potential rival by Stalin. By 1941, only 5% or fewer army and military district commanders had two years command experience following these purges.
By the 22nd of June 1941, just 1,475 modern T-34s and KV series tanks were available despite an authorized strength reaching no less than 29,899 tanks by 1941. Nearly three-quarters of armored vehicles were overdue for major maintenance and dispersed along front lines unable to provide mass for local success.
The Red Army began the invasion of Manchuria on the 9th of August 1945, which fell exactly three days after Hiroshima and the same day Nagasaki received an atomic bomb. This date also marked exactly three months after Germany surrendered and contributed significantly to ending World War II in the Pacific theater.